Relationship between M Φ activity and the growth of hepatocellular carcinoma (HCC) was been studied in 49 cases after operation. It was found that MΦ activity in the patients with tumor capsulated completely by fibrous tissue is significantly higher than that in the patients with tumor capsulated uncompletely. There is no significant difference on MΦ activity between the groups of large HCC and small HCC, and between groups of single nodule and multiple nodules. The results suggest that M Φ activity is closely related to the fibrous capsule of HCC, and MΦ maybe prevent HCC from spreading.